Load live version when reloading an offline page on connected network

chrome/browser/android/offline_pages/offline_page_tab_helper.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_TAB_HELPER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_TAB_HELPER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "components/offline_pages/request_header/offline_page_header.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "url/gurl.h"
 
 namespace content {
 class WebContents;
 }
 
 namespace offline_pages {
 
 struct OfflinePageItem;
 
 // Per-tab class that monitors the navigations and stores the necessary info
 // to facilitate the synchronous access to offline information.
 class OfflinePageTabHelper :
     public content::WebContentsObserver,
     public content::WebContentsUserData<OfflinePageTabHelper> {
  public:
   ~OfflinePageTabHelper() override;
 
-  const OfflinePageItem* offline_page() { return offline_page_.get(); }
   void SetOfflinePage(const OfflinePageItem& offline_page,
+                      const OfflinePageHeader& offline_header,
                       bool is_offline_preview);
 
+  const OfflinePageItem* offline_page() {
+    return offline_info_.offline_page.get();
+  }
+
+  const OfflinePageHeader& offline_header() const {
+    return offline_info_.offline_header;
+  }
+
   // Whether the page is an offline preview.
-  bool is_offline_preview() const { return is_offline_preview_; }
+  bool is_offline_preview() const { return offline_info_.is_offline_preview; }
 
   // Returns provisional offline page since actual navigation does not happen
   // during unit tests.
   const OfflinePageItem* GetOfflinePageForTest() const;
 
  private:
   friend class content::WebContentsUserData<OfflinePageTabHelper>;
 
+  // Contains the info about the offline page being loaded.
+  struct LoadedOfflinePageInfo {
+    LoadedOfflinePageInfo();
+    ~LoadedOfflinePageInfo();
+
+    // The cached copy of OfflinePageItem.
+    std::unique_ptr<OfflinePageItem> offline_page;
+
+    // The offline header that is provided when offline page is loaded.
+    OfflinePageHeader offline_header;
+
+    // Whether the page is an offline preview. Offline page previews are shown
+    // when a user's effective connection type is prohibitively slow.
+    bool is_offline_preview;
+
+    void Clear();
+  };
+
   explicit OfflinePageTabHelper(content::WebContents* web_contents);
 
   // Overridden from content::WebContentsObserver:
   void DidStartNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
 
   void SelectPageForOnlineURLDone(const OfflinePageItem* offline_page);
 
-  // The cached copy of OfflinePageItem if offline page is loaded for current
-  // tab. This can be used to by the Tab to synchronously ask about the offline
+  // The provisional info about the offline page being loaded. This is set when
+  // the offline interceptor decides to serve the offline page and it will be
+  // moved to |offline_info_| once the navigation is committed without error.
+  LoadedOfflinePageInfo provisional_offline_info_;
+
+  // The info about offline page being loaded. This is set from
+  // |provisional_offline_info_| when the navigation is committed without error.
+  // This can be used to by the Tab to synchronously ask about the offline
   // info.
-  std::unique_ptr<OfflinePageItem> offline_page_;
-  // Potential new offline page copy. This is reset to nullptr at the start
-  // of every navigation and set by network request interceptor. If the
-  // interceptor decided to not use offline page for the navigation or was not
-  // even invoked (as in case with fragment navigation), this stays nullptr.
-  std::unique_ptr<OfflinePageItem> provisional_offline_page_;
+  LoadedOfflinePageInfo offline_info_;
 
   bool reloading_url_on_net_error_ = false;
 
-  // Whether the page is an offline preview. Offline page previews are shown
-  // when a user's effective connection type is prohibitively slow.
-  bool is_offline_preview_;
-
   base::WeakPtrFactory<OfflinePageTabHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageTabHelper);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_TAB_HELPER_H_